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  <title>Seeks to specific location in a stream</title>

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</div><hr /><div id="streamwrapper.stream-seek" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">streamWrapper::stream_seek</h1>
  <p class="verinfo">(PHP 4 &gt;= 4.3.2, PHP 5)</p><p class="refpurpose"><span class="refname">streamWrapper::stream_seek</span> &mdash; <span class="dc-title">Seeks to specific location in a stream</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-streamwrapper.stream-seek-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="modifier">public</span> <span class="type">bool</span> <span class="methodname"><strong>streamWrapper::stream_seek</strong></span>
    ( <span class="methodparam"><span class="type">int</span> <code class="parameter">$offset</code></span>
   , <span class="methodparam"><span class="type">int</span> <code class="parameter">$whence</code> <span class="initializer"> = SEEK_SET</span></span>
   )</div>

  <p class="para rdfs-comment">
   This method is called in response to <span class="function"><a href="function.fseek.html" class="function">fseek()</a></span>.
  </p>
  <p class="para">
   The read/write position of the stream should be updated according to the
   <em><code class="parameter">offset</code></em> and <em><code class="parameter">whence</code></em>.
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-streamwrapper.stream-seek-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<em><code class="parameter">offset</code></em></dt>

     <dd>

      <p class="para">
       The stream offset to seek to.
      </p>
     </dd>

    
    
     <dt>
<em><code class="parameter">whence</code></em></dt>

     <dd>

      <p class="para">
       Possible values:
       <ul class="simplelist">
        <li class="member"><strong><code>SEEK_SET</code></strong> - Set position equal to <em><code class="parameter">offset</code></em> bytes.</li>
        <li class="member"><strong><code>SEEK_CUR</code></strong> - Set position to current location plus <em><code class="parameter">offset</code></em>.</li>
        <li class="member"><strong><code>SEEK_END</code></strong> - Set position to end-of-file plus <em><code class="parameter">offset</code></em>.</li>
       </ul>
      </p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-streamwrapper.stream-seek-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   Return <strong><code>TRUE</code></strong> if the position was updated, <strong><code>FALSE</code></strong> otherwise.
  </p>
 </div>




 <div class="refsect1 notes" id="refsect1-streamwrapper.stream-seek-notes">
  <h3 class="title">注释</h3>
  <blockquote class="note"><p><strong class="note">Note</strong>: 
   <p class="para">
    If not implemented, <strong><code>FALSE</code></strong> is assumed as the return value.
   </p>
  </p></blockquote>
  <blockquote class="note"><p><strong class="note">Note</strong>: 
   <p class="para">
    Upon success, 
    <span class="methodname"><a href="streamwrapper.stream-tell.html" class="methodname">streamWrapper::stream_tell()</a></span> is called directly after
    calling <span class="methodname"><strong>streamWrapper::stream_seek()</strong></span>. If
    <span class="methodname"><a href="streamwrapper.stream-tell.html" class="methodname">streamWrapper::stream_tell()</a></span> fails, the return
    value to the caller function will be set to <strong><code>FALSE</code></strong>
   </p>
  </p></blockquote>
  <blockquote class="note"><p><strong class="note">Note</strong>: 
   <p class="para">
    Not all seeks operations on the stream will result in this function being
    called. PHP streams have read buffering enabled by default (see also
    <span class="function"><a href="function.stream-set-read-buffer.html" class="function">stream_set_read_buffer()</a></span>) and seeking may be done by
    merely moving the buffer pointer.
   </p>
  </p></blockquote>
 </div>


 <div class="refsect1 seealso" id="refsect1-streamwrapper.stream-seek-seealso">
  <h3 class="title">参见</h3>
  <p class="para">
   <ul class="simplelist">
    <li class="member"><span class="function"><a href="function.fseek.html" class="function" rel="rdfs-seeAlso">fseek()</a> - 在文件指针中定位</span></li>
   </ul>
  </p>
 </div>


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